How to Cut Glass With a Dremel – Follow These Easy Steps

Dremels are well known for their ability to perform a wide variety of tasks. Simply change the attachment, and you can tackle many activities such as grinding, sanding, cutting various materials with the same tool. In this article, we’ll talk about how to cut glass using a Dremel rotary tool.

One of the most difficult materials to deal with is glass, no doubt. There are a few occasions when you might need to cut glass. For example, to adjust a bottleneck for a DIY project, or to reshape an old mirror. In any case, there’s always the risk you’ll end up shattering the thing. That’s why you need to use the right tool and the correct approach. If you happen to own a Dremel, then using it for cutting glass is definitely a good idea.

“Dremel 3000” by ghalfacree is licensed under CC BY 2.0

For the best results, make sure to follow these steps:

  • Get yourself a cutting bit for glass. A diamond wheel like the EZ545 will do the trick;
  • Prepare for cutting. Take all the safety precautions needed; apply some tape along the line you want to cut, and mark it with a pencil;
  • Now it’s time to do the cutting. Put the glass under running water when cutting. Use a high RPM, but low pressure. Finally, smooth the edges with a Grinding Stone (or some sandpaper).

Now let’s take each one of them and go into details.

How to Cut Glass With a Dremel – Step by Step Guide

1) Choose the Appropriate Bit for Glass

Using the correct attachment is basically half the job you need to do. Since Dremel has so many accessories available, it might be quite a daunting task to choose the correct one. To make your life easier, I did the research for you. Choose between one of the following bits, depending on the task you are about to perform:

  • EZ545 1-1/2-Inch Diamond Wheel. You should get this cutting wheel if you need to perform long, straight cuts. It will also do a fine job on other materials such as marble, concrete, and tiles. It’s a good multipurpose wheel for any hard material you can think of. The version I linked (EZ545) has a diameter of 1-1/2″ or 38.1 mm, while the 545 is a bit smaller: 7/8″ or 22.1 mm. Choose accordingly to your application. Alternatively, any diamond-coated wheel will work just fine.
  • 662DR 1/8-Inch Glass Drilling Bit.  This bit will come in handy for cutting holes in glass. It’s made of metal, with a diamond-coated tip, which makes it super durable. For bigger holes, get the 663 version, which is 1/4″ wide.

Basically, you need either a diamond-coated wheel for cutting along a line or a diamond-coated bit for drilling holes. These attachments are quite expensive: good thing they are pretty durable. They don’t break as easily as other Dremel attachments. So it’s well-spent money.

Lastly, consider getting a Flex Shaft Attachment, for two reasons. First, it’s easier to move it around; second, we will use water when cutting, and you want to keep the Dremel away from it. Other than that, it’s definitely a solid addition to your Dremel attachments arsenal. It comes super handy when cutting things in narrow spots, or overhead.

2) Prepare Yourself and the Project for the Cutting Phase

Before we get to the cutting phase, make sure you take into consideration the following points:

  • Cutting glass is no joke. It’s important to take all the necessary safety precautions. Make sure to wear glasses and a face mask to protect yourself from flying glass particles; don’t forget to wear gloves to protect your hands in case of shattering.
  • For safety reasons and the best results, clamp down the glass before you start cutting.
  • Apply some tape along the line you intend to cut. This will be helpful for a couple of reasons: first, it will keep glass debris from flying all around the place; second, it will guarantee a cleaner cut since it lowers the chance of bigger particles detaching from the cutting area. What type of tape should you use for this kind of application? In my experience, paper tape works great. It has good adhesive properties without leaving too much residue behind when removed.
  • Mark the line you intend to cut on the tape. This will help you stay on track, avoiding unpleasant mistakes. Make sure to wait until the ink is completely dry before moving on to the next step.

3) Cutting Steps

After all the preparation part, it’s finally time to get to the cutting. Here are some tips to maximize your results:

  • Place your piece under running water when cutting. It will keep things cooler, minimizing chances of breakage, and the cutting bit will last longer. On top of that, it will also reduce the amount of debris flying around, which is key when dealing with glass. Consider using a Flex Shaft Attachment to minimize the chance of water ending up on your rotary tool.
  • Always advance against the rotation of the disc. If you do the opposite, the tool will “run away”.
  • You should always keep both hands on the tool when operating it; if you are cutting a bottle, pin it in some way. Don’t use one hand to hold it down.
  • When cutting glass, ideally you’d want to keep a high speed, since it will keep the glass from shattering. Problem is that at very high speed, the Dremel will get quite hard to control and it will start to wobble around. As always, you’ll need to compromise. A good starting point would be starting at around 20.000 RPM. Adjust it accordingly to the attachment you are using and the application at hand.
  • Apply the minimum amount of pressure needed to get the tool cutting. Let it do its thing, be patient with it. Too much pressure applied to the glass is likely to break it.

4) Smooth the Edges

When you are done cutting, it’s certainly a good idea to smooth the edges out a bit. When cutting with a diamond wheel, chances are the edges will end up looking pretty rough. On top of that, some portion of them is likely to be quite sharp. You have two options to get this done:

  • Use a Dremel grinding attachment. Since you’ll be grinding a non-ferrous material, you’ll have to use a silicon carbide grinding stone. It’s tougher than the aluminum oxide counterpart which is usually used on metals. A good starting point might be the 83142 Grinding Stone. There are other sizes and shapes available: choose according to your application. Use a very low RPM when using these grinding stones: you don’t want to remove too much material.
  • If you don’t have a grinding stone and you don’t want to get one, you could also use some sandpaper to smooth the glass edges. Start with a coarse grit, around 100, then move up into the 200s.

In any case, remember to use a light touch. You are working on thin, easily breakable edges, and you certainly want to avoid that.

How to Drill a Hole in Glass With a Dremel

What about cutting holes in glass? The steps to take are quite similar. We already talked about the attachment choice. Same as with the cutting wheel, you are supposed to use a diamond-coated bit for drilling, such as the 662DR.

After getting the right bit, prepare for the cutting: place the glass under running water, or use a bowl full of water if the piece is small enough. Make sure you are drilling on a firm surface: place a piece of wood under the glass to increase stability and to avoid drill the bowl/table.

Finally, it’s time to drill. Make sure to use a low setting speed. Don’t apply too much pressure, let the bit cut its way through.

What about tempered glass? Unfortunately, you can’t drill that. It may look fine when you start, but at some point, it will completely shatter. The only thing you can do with it is edge working.

FAQs (Frequently Asked Questions)

What’s the best Dremel bit for cutting glass?

When cutting hard materials like glass, you need to use a cutting disc which is also very tough. That’s why it’s important to use a diamond wheel for this kind of activity. My go-to choice for materials like glass, marble, concrete is the EZ545 1-1/2-Inch Diamond Wheel. It’s high quality and pretty durable considering the materials you use it on. Alternatively, any diamond-coated wheel will do the trick for cutting glass.

How to cut a mirror with a Dremel?
“mirror” by Paul Keller is licensed under CC BY 2.0

When cutting large glass objects like mirrors, the steps to follow do not differ from what I detailed before: the key passages are using a diamond cutting wheel and using tape and water to avoid shattering.

In this scenario, you need to be even more careful when pressing onto the surface while cutting. You need to make sure the cutting piece is stable. Ideally, you’d want to remove any frame around the mirror and place it on an even wooden board. Then, carefully cut the desired shape while spraying water on top of it. If your mirror is too big for a bowl or your sink, use a hose to keep the cutting area wet. Alternatively, cut a small hole on the side of a plastic bottle, and use it as a waterer.

Can you grind glass with a Dremel?

Yes, as I told you before, it’s totally safe to grind glass with a Dremel. It’s just a matter of using the right accessory (in this case, a Grinding Stone) and some precautions, like applying water to the surface to avoid debris build-up. It also helps to keep the glass cool, preventing shattering.

Even if you are using water, don’t forget to wear safety gear like glasses and a face mask. You don’t want to take the risk of breathing glass particles.

Final Thoughts

At this point, you have all the information you need to cut glass with your Dremel safely. When cutting stuff like wood and metal, there’s very little that can go wrong: the worst that can happen is getting sidetracked by the tool, ending up with an ugly cut.

When cutting glass, shattering is always behind the corner. That’s why you need to be super careful with it. Let’s sum the step to take to minimize this risk:

  • Apply some tape to the cutting area. This will help prevent any shattering;
  • Use little pressure when cutting and fining/sanding, especially if you are working on thin glass;
  • Make sure there’s no heat build-up. To avoid that, place your glass under water while cutting.

That’s it for this article, see you in the next one!

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